
TY  - JOUR
A1  - Cameron, DW 
A1  - Crossley, MJ 
A1  - Feutrill, GI 
A1  - Griffiths, PG 
T1  - Nucleophilic alkenes. III. Addition of 1,1-dialkoxyethenes to 1,4-naphthoquinones. The 1 : 2-process
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1978
VL  - 31
IS  - 6
SP  - 1335
EP  - 1352
KW  - 
UR  - https://doi.org/10.1071/CH9781335 
N2  - Anthraquinones have been synthesized by 1 : 2-addition of 1,1- dialkoxyethenes to 1,4-naphtho-quinones, prior bromination of the naphthoquinone being unnecessary. The reactions were markedly accelerated by polar solvents and there was orientational specificity in most cases. Addition to 5-hydroxy-1,4-naphthoquinones gave derivatives of 1,3,8-trihydroxyanthraquinone while 5-methoxy-1,4- naphthoquinone gave the 1,3,5-substitution pattern. 6-Hydroxy- and 6- alkoxy-naphthoquinones gave chiefly the 1,3,7-orientation, appropriate prior bromination being required to generate the 1,3,6-series. These orientations are interpreted in terms of initial nucleophilic attack of 1,1-dialkoxy-ethene at a quinonoid carbon. This also takes into account concurrent 1 : 1-addition processes. 
ER  -

